EXOGENUS ‘GA3’ AND ‘GA4+7’ EFFECTS ON PHENOLOGICAL INDICES, FROST HARDINESS AND QUALITY PROPERTIES OF ‘ENGLISH MORELLO’ SOUR CHERRY (Prunus cerasus L.)

Abstract

Exogenous gibberellins GA 3 and GA 4+7 treatments on 'English Morello' sour cherry trees 58 days after anthesis were evaluated in relation to their effect on fruit firmness, size distribution, colour development, titratable acidity to firmness ratio, yield, efficiency indices as well as leaf fall senescence. Moreover in the season following the applications their effect on flower bud characteristics including frost hardiness, fruit set and fruit drop, were examined. Foliar GA 3 treatment had the most positive effect on 'English Morello' fruit size in the year of application and in the following season. GA 4+7 treatment in the first experimental year increased sour cherry fruit firmness. Both GA 3 and GA 4+7 delayed leaf senescence process in the autumn. GA 3 application had a positive effect on flower buds survival in comparison to control trees after frost occurred in spring. No GAs subsequent effect on next year fruit set and yield compared to control was found.

GA3 Treatment Delays the Deterioration of ‘Shixia’ Longan during the On-Tree Preservation and Room-Temperature Storage and Up-Regulates Antioxidants

“…These results indicated that the GA 3 treatment significantly affected total soluble solids, antioxidants, and related enzyme activities in longan fruit during ripening and on-tree preservation. In recent years, preharvest or postharvest GAs application has attracted much attention in postharvest technology of fruits, due to their positive regulation of fruit size [13,[16][17][18][19][20], firmness [16,20], anthocyanin content [11], and PAL activity [11], as well as inhibition effect on respiration rate [15,20], postharvest ripening [15], and deterioration [9,15]. In this study, we found that preharvest GA 3 treatment with an appropriate concentration (50 mg L −1 ) led to decreased TPC, TFC, and PAL activity (similar to the results reported in the GA 3 -treated grape berry skin and flesh [13] and cherry [17]) in longan pulp at the mature stage.…”

“…The above results indicated that the 50 mg L −1 GA 3 treatment significantly improved the storability of 'Shixia' longan fruit. In addition to the reported effect of GA3 on fruit quality (strawberry [11], 'French' prune [12], grape berry [13], pear fruit [14], cherry [17], sour cherry [18], "Washington Navel" orange [19], jujube fruit [20]) at harvest, as well as the maintenance of VC and phenolic substances after harvest, preharvest treatments with oxalic acid (on sweet cherry [32] and lemon fruit [33]), melatonin (on pomegranate [34]), and methyl jasmonate (on plum [35]) were proven to improve fruit quality and storability, stimulate the antioxidant system, and enhance accumulation of bioactive compounds. In this study, the longan fruits for the storage experiment were sprayed with 50 mg L −1 GA3 or the control solution 2 times (at 85 DAF and 95 DAF) and harvested at 105 DAF.…”

“…Another document showed that 30 or 60 mg L −1 GA 3 spraying on cherry at straw-yellow stage significantly enlarged the fruit size, but generally led to lower SSC, as well as significantly lower TPC, total anthocyanin content, and total antioxidant capacity [17]. Both of the 30 mg L −1 GA 3 and 30 mg L −1 GA 4+7 spraying on the whole canopies of 'English Morello' sour cherry trees at 58 days after anthesis (DAA) delayed leaf senescence, and GA 3 treatment had a better positive effect on the fruit size in two consecutive years [18]. The foliar application of 50 mg L −1 GA 3 plus 10 mg L −1 CPPU on "Washington Navel" orange trees at 15, 30, and 45 days after full bloom gave the highest fresh weight, length, yield, and SSC (%) of fruit, while 50 mg L −1 GA 3 plus 50 mg L −1 BA resulted in the greatest diameter, content of chlorophyll, TA (%), and vitamin C (VC) content, as well as decreased splitting (%) and carotene content in fruit [19].…”